1. Field of the Invention
The present invention generally involves the field of technology relating to protective devices for valved fittings projecting outwardly from a fluid container. More particularly, the invention relates to an improved protective cap assembly for the valved fitting of a pressurized fluid cylinder.
2. Description of the Prior Art
A conventional cylinder for containing pressurized fluids, such as oxygen and flammable gases, are provided at one end with a discharge opening through which the fluid is dispensed by means of a valved fitting. The fitting includes a manually operated valve that is supported on a cap ring and an associated collar secured to the cylinder. The cap ring is provided with male or external threading that is engageable by corresponding female or internal threading provided in a dome-shaped cap used for protecting the fitting. This protection is critical since the fluid stored within the cylinder is under high pressure so that a rupturing of the fitting from severe impact during handling may result in serious injury to personnel or damage to property.
The conventional threaded engagement between a protective cap and its associated valved fitting, although sufficient to meet minimum safety standards, nevertheless does have certain disadvantages. Since the cap is normally formed of steel, the threading in the cap has a tendency to corrode, thereby rendering it difficult to attach and remove the cap. Although the basic function of the cap is to protect the fitting from damage caused from a severe impact, such impact may nevertheless cause the corresponding threads of the cap and fitting to be deformed, thus rendering it difficult to remove the cap. Moreover, the nature of the threaded connection requires a significant amount of time and effort during removal or attachment of the cap.
These disadvantages of a threaded connection have been well recognized over the years and there have been attempts to design and construct threadless protective caps which are not only easier to attach to and remove from the cylinder, but also are capable of meeting the safety standards required of such caps. For example, it is known to provide a threadless cap which is secured to the cylinder by means of a bayonet-type connection. It is also known to provide caps which have hinged sections that pivot into an open position to permit access to the valved fitting. Other types of interconnection arrangements between the cap and cylinder have also been proposed, most of which require rotational movement of the cap in order to effect its locking engagement.